Living high and training low

[This article originally appeared in the
September 2000
issue of Northwest Runner
magazine.]

High-altitude training is admittedly a complex topic. At its
core, however, it is basically a "natural" form of blood doping.

So what is blood doping? Does it really improve endurance
performance? And is altitude training a sensible alternative? Let's
address each of these questions in turn.

The term "blood doping" refers to the practice of increasing the
number of red blood cells (RBCs) in one's circulatory system, either by
receiving a blood transfusion or by taking erythropoietin ("epo" for
short), a hormone that promotes RBC production. Since RBCs carry oxygen
from the lungs to the rest of the body, adding more of them to one's
circulation should enhance the delivery of oxygen to one's muscles.
Improved oxygen delivery, in turn, might help the muscles perform
better.

While the above paragraphs make blood doping sound wonderful, it
has some serious drawbacks. It can be life-threatening if performed
without appropriate medical supervision; it is generally considered to be
a form of cheating; and it is forbidden by many athletics governing
bodies. (Details can be found in the American College of Sports
Medicine's position stand on "The Use of Blood Doping as an Ergogenic Aid"
[Medicine
and Science in Sports and Exercise 28: i-viii, 1996].) For these
reasons, among others, many athletes have turned to altitude training as
an alternative to blood transfusions and erythropoietin
treatments.

It is well established that the human body responds to
high-altitude, low-oxygen environments by producing more RBCs. Thus, by
living well above sea level, athletes may improve their oxygen-carrying
capacity -- and presumably their sea-level performances as well -- in a
safe and ethical manner.

Given these complications, Levine & Stray-Gundersen have
proposed a "live high, train low" model of altitude training in which
athletes live at high altitude but drive down to lower elevations for
their runs. The main goal of this model is to allow athletes to increase
their RBC production while also allowing them to maintain the quality of
their training.

The effectiveness of the "live high, train low" approach has now
been verified in a thorough report (Levine
& Stray-Gundersen, Journal of Applied Physiology 83: 102-12, 1997)
based on several years of work. In this exhaustive study, 39 competitive
runners (27 men and 12 women) were divided into three groups: "live low,
train low," "live high, train high," and "live high, train low." While
the methodological details are beyond the scope of this article, the key
finding was that the "live high, train low" runners improved their 5K
times by an average of 13 seconds after four weeks of living high and
training low, whereas the other two groups did not get faster.

Individual results may vary

Although the "live high, train low" program appears to bolster the
fitness of trained runners, a follow-up study (Chapman
et al., Journal of Applied Physiology 85: 1448-56, 1998) revealed that
individuals vary greatly in their responses to altitude. Thus, not all
athletes will benefit equally from living high. Furthermore, it is
possible that different individuals may be best suited to different
elevations. In their 1992 article, Levine & Stray-Gundersen speculated
that altitudes of 2,200 to 4,000 meters (7,200 to 13,100 feet) might be
optimal for most athletes. They are continuing to explore this issue in
their current research, however, and we can expect a more definitive
recommendation from them within the next couple years.

Also yet to be resolved is the question of how long one should
live at altitude in preparation for a subsequent sea-level race. The
"live high, train low" studies mentioned above included four weeks of
living high, so four weeks is evidently enough to benefit most athletes.
Berglund (Sports Medicine 14: 289-303, 1992) has argued that sojourns of 10 to
12 weeks may permit more complete cardiovascular adaptations than can
occur during a four-week training camp. This viewpoint is based on
limited data, however, and has not yet been tested in a full-scale
investigation. In addition, the ideal duration of a visit to high
altitude may depend on the altitude at which one is staying.

A final point concerns the use of hypoxic (low-oxygen) chambers.
Many top athletes sleep in these chambers in order to expose themselves to
high-altitude conditions without having to move to the mountains.
However, the efficacy of this tactic has been called into question by two
recent studies (Ashenden
et al., European Journal of Applied Physiology 80: 472-8, 1999; Ashenden
et al., European Journal of Applied Physiology 80: 479-84, 1999) in
which 12 to 23 nights in a low-oxygen "nitrogen house" failed to boost RBC
production in a group of Australian cyclists, skiers, and triathletes.
It is possible that spending eight to ten hours per day in high-altitude
conditions is simply not enough to "trick" the body into adapting to high
altitude. (For more on this topic, please see my July 2001 column.) Clearly, while much has been learned about altitude training,
much remains to be discovered as well. Stay tuned; the next few years
should be interesting!